This article presents an experimental apporach for the determination of the adsorption isotherms of methane on activated carbon that is essential for methane storage purposes. The experiments incorporated a constant-volume-variable-pressure (CVVP) apparatus and two types of activated carbon have been investigated namely, activated carbon derived from the low rank coal of the East of Kalimantan, Indonesia, and a Carbotech activated carbon. The isotherm results which cover temperature from (300 to 318) K and pressures up to 3.5 MPa are analyzed using the Langmuir, Toth, and Dubinin-Astakhov (D-A) isotherm models. The heat of adsorption, for the single component methane-activated carbon system, which is concentration- and temperature-dependent, is determined from the measured isotherm data.